Technical Brochure - Envu Ronstar - 231113

Great Weed Control Without Root Pruning

Physically controlling and removing weeds in nurseries is a major task that carries a large financial cost. Weeds compete for water and nutrients and can substantially reduce plant growth and quality. Ronstar® is a highly selective granular pre-emergent herbicide that can be used at plant establishment. It does not affect root systems and therefore offers a flexible approach to effective, economic weed control giving faster plant establishment and growth.

Weeds Controlled

Bittercress (Flickweed), Creeping Oxalis, Petty Spurge, Sorrel, Sowthistle, Trefoils, Willow Herbs, Winter grass. In turf: Crowsfoot Grass, Summer Grass, Winter grass, Creeping oxalis.

Areas of Use

Container–grown woody ornamental tree, shrubs and vines. Transplanted field grown ornamental crops (NSW only). Recreational turf including golf fairways, municipal sports fields, industrial and commercial lawns.

Application Rate and Delivery

• 150 or 200 kg/ha
• Refer also to the table showing rates for individual container sizes

How to Apply

Ronstar should be applied using a properly calibrated granular applicator which will apply the granules in a uniform pattern producing a high standard of weed control. Calibrate according to the machinery manufacturers instructions and recheck the applicator at regular intervals to ensure equipment is performing properly. Overhead irrigation following application will improve weed control activity and distribute chemical evenly. Ronstar should not be applied to wet foliage.

Rate for Individual Container Sizes

Key Features

• Is not taken up by roots – does not affect root systems (no root-pruning) and is not translocated through the plant
• High level of selectivity – allowing use in a wide range of ornamental species
• Kills weeds prior to emergence from soil
• Controls germinating weeds for up to 10 weeks giving season long weed control
• Does not degrade after exposure to long periods to sunlight, therefore weed control is maintained for a long period
• Oxadiazon becomes strongly bound to soil humic and clay particles and therefore does not leach from the soil under heavy irrigation or rainfall
• Retains activity over a range of soil types, organic matter and pH
• Degraded in soil via microbial pathways – research shows no evidence of build up of oxadiazon in soil after several annual applications

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Great Weed Control Without Root Pruning

Ronstar Can Be Used on a Wide Variety of Ornamental Species

Best Practice Guidelines

Apply to soil surface of newly potted or freshly weeded containers. Repeat applications may be made at 10 week intervals. Apply to freshly weeded flower beds. Repeat applications at 10 week intervals. Apply prior to germination of the weeds (usually from late summer to mid-autumn, February to May, and early spring, August to October), do not overwater pots (moving the particles around the soil surface). Remove granules from plant material via blowing or irrigation.

Product Profile

Active Ingredient 20 g/kg Oxadiazon Insecticide group Group 14 Oxidiazole group Formulation type Granule Pack size 15 kg (box) Personal protective equipment required: None.

Regulatory Information

APVMA Product Number: 62461 Poisons Schedule: Schedule 6

Impact on the Environment

All pesticides are regulated under the Agricultural and Veterinary Chemicals Code Act 1994 to ensure that they do not pose an unacceptable risk to human health and the environment. For more information regarding the pesticide regulatory process please visit the Australian Pesticides and Veterinary Medicines Authority website at

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ALWAYS READ THE LABEL BEFORE USE Ronstar® is a trademark of 2022 Environmental Science AU Pty Ltd Suite 2.06, Level 2, 737 Burwood Rd, Hawthorn East, VIC. 3123 Technical Enquiries: Envu and the Envu logo are trademarks owned by Environmental Science U.S. LLC., or one of its affiliates © 2023 Environmental Science U.S. LLC.